Conductive shoe



Feb- 26, 1963 c. MaGQUAlD ETAL CONDUCTIVE SHOE Filed July 6, 1959 United States Patent Oliice 3,079,153@ Patented Feb. Z6, 1963 3,679,53@ CQNDUCTVE SHGE Craig MaeQuaid, Clayton, land Leslie lt. Heideman, Normandy, Mo., assignors to International Shoe Sonn pany, St. Louis, Mo., a corporation of Delaware Filed July 6, 1h59, Ser. No. 825,314 3 Claims. (Cl. S17-WZ) The present invention relates generally to the shoe art, and more particularly to a novel conductive shoe incorporating a molded or vulcanized shoe bottom providing a physically continuous electrically conductive construction from the outsole and heel to and including the soci: lining contacting the wea-rers foot, and to a method of constructing such a shoe.

Heretofore conductive shoes adapted to ground static electricity accumulated in the body of the wearer have long been used in industries where static charges may adversely atleet the work eiiiciency of the Workmen, or may set oil an explosion, as in operating rooms, powder plants, and other areas. Various improvements have been made in conductive shoes, but one or more disadvantages are inherent in constructions now available. Where conductive cements are used, separations will inevitably occur. Where conductive plugs are used to join parts of the shoe, high or low spots will develop in the shoe which is uncomfortable for the wearer.

Therefore, an object :of the present invention is to provide a novel electrically conductive shoe which overcomes the disadvantages inherent in electrically conductive shoes now available `for use.

`in brief, the present novel electrically conductive shoe includes a molded or vulcanized electrically conductive bottom. In superposed relation are a conductive sock lining, a perforated insole, a perforated shank, `a heel ller, and an electrically conductive elastomeric integral heel and outside molded and vulcanized to the lasted upper, lilling the perforations of the insole and curing to the sock lining to create an integral, electrically conductive shoe bottom.

Another object of the present invention is to provide a novel electrically conductive shoe incorporating a molded and vulcanized outer sole and heel having integral portions extending upwardly through provided openings in an insole and shank fused with an electrically conduc- 'tive sock lining.

Another object is to provide a novel electrically conductive shoe incorporating fused electrically conductive material between an electrically conductive sock lining and electrically conductive outer sole providing a continuous electrical circuit for grounding static electricity.

Another object is to provide a novel method of constructing or forming an electrically conductive shoe, particularly the bottom part thereof.

Another object is to provide a novel method of forming predetermined portions of a shoe bottom portion.

Another object is to provide a novel electrically conductive shoe incorporating a continuous integrated physical path for the conduction of static electricity from the wearer -to ground.

Other objects are to provide a novel electrically conductive shoe in which the bottom portion is of sturdy construction to provide a continuous electrical path for electricity from the foot of the wearer to ground for substantially the life of the shoe, which is effective `tor Iits intended purpose in grounding static electricity, which eliminates juncture planes in the electrical path between the outer sole and sock lining of the bottom portion, and which otherwise fullls the objects and advantages sought therefor.

The toregoing Iand other objects and advantages are d apparent from the following description taken with the accompanying drawing, in which:

FIGURE l is a perspective view of an electrically conductive shoe Iincorporating the teachings of the present invention;

FIGURE 2 is a plan view of an electrically conductive sock lining;

FlGURE 3 is a plan view of an insole incorporating a Iplurality of openings;

FEGURE 4 is a plan view of perforated shank;

FIGURE 5 is a side elevational view of the perforated shank of FIGURE 4;

FIGURE 6 is a plan view of a fiber heel ller;

FIGURE 7 is an enlarged fragmentary central longitudinal cross-sectional view through the shoe of FIG- URE l;

FIGURE 8 is a transverse cross-sectional View taken `on substantially the line 3 8 of FIGURE 7;

FIGURE 9 is a vertical, transverse, cross-sectional View taken on substantially the line 9 9 of FIGURE 7; and

FIGURE l() is a vertical, transverse, cross-sectional View taken on substantially the line lillil of FIGURE 7.

Referring to the drawing more particularly by reference numerals, lr6 indicates generally an electrically conductive shoe including the teachings of the present invention. The shoe i6 includes a conventional upper 18 and a novel shoe bottom 2li.

The shoe bottom 2% comprises an electrically conductive sock lining 22, an insole 24 having openings 2.6 therethrough, a shank 28 having openings 3G therethrough, a liber heel filler 32, an electrically conductive outsole 3d, and `an electrically conductive heel 36 integral with the outsole 3d. Integral with the outsole 34 and the soci; lining 22 are electrically conductive connecting plugs 38 which extend through the insole openings 26 and the shank opening 3d, as is clear from FIGURES 7, 8 and 9.

In making the present novel shoe le, the upper I8 is lasted to the perforated 4insole 24 on a Wooden last by conventional shoe making operations. After the shoe upper has been roughened ou lthe bottom for attaching purposes, the lasted shoe upper is removed from the wooden last and a vu-lcanizabie adhesive is applied to the roughened surface. The electrically conductive sock lining 22 is prepared with a suitable electrically conductive vulcanizable adhesive on the attaching side and is positioned within the shoe against the perforated insole 24. rl`he prepared lasted upper, having the above-mentioned parts and preparation, is placed upon a metal last which is a part of the molding and vulcanizing machine.

The shank 2S, and the heel iiller 32, are anchored to the bottom of the insole by the struck-out prongs 40 so that the perforations of the shank 28 are aligned With the perforations of the insole 212). Vulcanizable, electrically conductive, elastomeric compound, which is to :be molded to form the outsole 34 and heel 36, is placed within the heated mold consisting of a bottom plate and side rings and the metal last covered by the shoe upper i3 is positioned with respect to the side rings of the mold. The mold is closed, sealing against the lasted upper iti, and heat and pressure applied in the usual manner of molding and vulcanizing equipment to force the heat softened compound through the openings 3d and 26 into engagement with the sock lining 22 to fuse thereinto and to become integral therewith. The metal last serves as the suitable backing element applied against the upper surface of the sock lining 22 and insole 24 to retain the rubber against the exerted pressure. The outsole 34 and the heel 36 are molded to the desired coniigurations. In the vulcanizing process, they become securely attached to lall portions of the insole 24, the shank 2.8, the iiller 32, and the upper IS, which are engaged by the rubber material.

It is clear `from the foregoing that a continuous physical electrical path is formed which includes the sock lining 22, the plugs 38, the outsole 34, and the heel 36. There are no adhesively connected planes which may become separated. The aforementioned four elements of the shoe bottom are integral. Hence, for the lifey sof the shoe 16, there -is assuredA an electrical path for discharge of static electricity from the wearer.

Itis Imanifest that the placement, number and size of the openings 26 and 30 may be varied as desired, and that the composition .andform of the conductive rubber maybe varied.

It is to be understood thatV Ithe' foregoing description and the accompanying drawing have been given by way of illustration and example. It is also to be understood that changes in formof the severalv parts, substitution of equivalent elements or'steps, and rearrangement of` parts or steps, which will be readily apparent to one skilled in the art, are contemplated as within the scope o f the present invention, which is limited only by the claim-s which follow.

What is claimed is:

l. Anelectrically conductive shoe including an insole, perforations in said insole, a sock lining ofVv electrically conductive material, an outsole of` electrically conductive material, and electrically conducting plugs extending into said perforations -frorn said outsole, said plugs lbeing integral with said outsole and said sock lining and adapted to conduct static electricity from a wearer into said outsole.

2. An electrically conductive shoe including an insole, perforations in said insole, a sock lining of electrically conductive material, a shank having perforations therein secured `beneath said insole with the perforations of said insole and shank aligned, an `outsole `of electrically oonductive material, and electrically conducting plugs extending into said perforations from said outsole, said plugs :being integral with said outsole andsaid sock lining and adapted toconduct static electricity from 'a wearer into said outsole.

3. A method .of forming an electrically conductive shoe comprising molding to an upper an outsole of electrically conductive material, and integrating an integral portion of said material While fluid with a provided sock lining of electrically conductive material, 

1. AN ELECTRICALLY CONDUCTIVE SHOE INCLUDING AN INSOLE, PERFORATIONS IN SAID INSOLE, A SOCK LINING OF ELECTRICALLY CONDUCTIVE MATERIAL, AN OUTSOLE OF ELECTRICALLY CONDUCTIVE MATERIAL, AND ELECTRICALLY CONDUCTING PLUGS EXTENDING INTO SAID PERFORATIONS FROM SAID OUTSOLE, SAID PLUGS BEING INTEGRAL WITH SAID OUTSOLE AND SAID SOCK LINING AND ADAPTED TO CONDUCT STATIC ELECTRICITY FROM A WEARER INTO SAID OUTSOLE. 